8.5.10 Optimizing InnoDB for Systems with Many Tables

InnoDB computes index
cardinality values
for a table the first time that table is accessed after
startup, instead of storing such values in the table. This
step can take significant time on systems that partition the
data into many tables. Since this overhead only applies to
the initial table open operation, to “warm up”
a table for later use, access it immediately after startup
by issuing a statement such as SELECT 1 FROM
tbl_name LIMIT 1.